1. Field of the Invention
The present invention relates to web browsers. More specifically, the present invention relates to a method and an apparatus that enables a web-based client-server application to be used offline.
2. Related Art
Scripting languages and dynamic components are often used in web pages to provide complex functionality to a user. Web servers process many of these scripts and components, and send the resulting output HyperText Markup Language (HTML) code to a browser for display to the user. However, this type of client-server web application requires a connection to the web server to be able to use the client-server web application.
In order to facilitate offline browsing, browsers typically provide a caching mechanism which enables every web page that is delivered to the browser to be stored in a browser cache. At some subsequent time, if the user attempts to view a previously viewed page and the client does not have a connection to the web server that hosted the web page, the browser can retrieve a copy of the web page from the browser cache and can display the copy of the web page to the user.
Modern web applications deliver display logic and data to the browser, such as JavaScript with HTML. Sometime this data has been preformatted for display purpose and sometimes the data is very raw. In either case, the files that are cached are only a snapshot of the data at one point in time, and may be irrelevant to the user at a subsequent time. Moreover, in many instances, the web application prevents this data from being cached.
Consider the example of a browser-based email application. If the browser cache only contains a static representation of the web page from the last time the user visited the browser-based email site, then the web page retrieved from the cache will not be very useful to the user. If the user is only presented with static representations of what was previously viewed, and the server-side logic is not being executed, then the user's actions on the cached pages do not result in the actions intended by the user. Moreover, this can lead to confusion because the user might believe that he or she performed some action that was actually not performed because the server-side logic was not executed.
Hence, what is needed is a method and an apparatus for viewing dynamic web pages in a browser without the problems listed above.